Smart city oriented ecological corridor layout of Sanshui River Basin in arid area of Loess Plateau

Abstract

Ecological corridor is an important means to maintain the stability of watershed ecosystem and enhance the ecological sustainability of watershed. The layout of ecological corridor can reduce the harm of landscape fragmentation caused by the rapid development of cities, especially in the arid area of Loess Plateau, which is of great significance to strengthen the connectivity of ecological patches and restore the service function of ecosystem. In this paper, taking Sanshui River Basin in Xunyi as the research object, from the perspectives of production, life and ecology, based on the landscape ecology research paradigm of “patch-corridor-matrix”, the ecological source is determined, the ecological corridor is identified and constructed by the method of overlapping ecosystem services and ecological sensitivity, and finally the spatial structure of ecological corridor network in Sanshui River Basin is obtained. The results show that 65 core ecological patches can be selected as key ecological sources in Sanshui River Basin. It is identified that 75 ecological corridors form an ecological corridor layout mode of “green corridors are coherent and loops are interconnected”; According to the layout of ecological corridor, the spatial structure of ecological corridor network can be formed as “one heart, one vertical and three horizontal”. The research can improve the ecological stability of Sanshui River Basin, promote the construction of ecological civilization in Sanshui River Basin, and provide scientific basis for the optimization of rural ecological space in small watershed scale.

Introduction

Ecological corridor has ecological functions such as preventing soil erosion, conserving water sources, regulating rural climate and protecting biodiversity, etc. Its layout is an important part of promoting ecosystem protection and restoration, and an important guarantee for ecological restoration and sustainable development from the perspective of globalization. In the process of optimizing the development of ecological space and promoting the construction of ecological civilization, it is necessary to determine the spatial layout and control measures of ecological corridor by delineating the control boundaries of production, living and ecological space. In recent years, affected by climate change and human activities, the soil in the Loess Plateau is dry, water resources are scarce [1], [2], and ecological problems have become increasingly serious [3], [4]. With the high-intensity human development activities, some important ecological corridors have been blocked, and the contradiction among economic development, ecological construction and human activities has become increasingly prominent [5], [6], which has had a direct impact on the sustainable development of the river basin. At present, some scholars have solved the problem of regional resource shortage and ecological space destruction by constructing ecological corridor from three aspects of production, life and ecology, which provides reference for related research and practical exploration [7]. Therefore, finding the layout method of ecological corridors in the Loess Plateau is indispensable for ensuring the scale and quality of the ecological space at the basin scale and realizing the sustainable development of the basin.

The concept of ecological corridor originated from the United States in the late 19th century. Many countries and organizations in the world have actively carried out large-scale corridor construction, such as ecological corridor construction [8], [9], North American greenway construction project [10], etc., and foreign scholars have made considerable achievements. Although the research on ecological corridor started relatively late in China, there are some research foundations at present, including discussing the connotation of corridor, identifying and constructing potential corridor, and then studying the spatial layout and promotion strategy of corridor with specific cases. The theory of corridor construction is mainly based on the theory of “patch-corridor-matrix” [11]. With regard to the research methods of corridors, comprehensive index evaluation method, direct identification method or minimum cumulative resistance model method are used to identify potential corridors, among which the minimum cumulative resistance model (MCR) is most frequently used [12]. Yu Kongjian et al. (1999) combined the minimum cumulative resistance model with GIS technology, which can further study the construction of ecological corridors. Most other scholars have built functional corridors such as heritage corridors [13], green infrastructure corridors [14], recreation and sports corridors [15], traditional village cultural landscape security corridor system [16], [17], green space ecological corridor [18], [19] and biodiversity protection corridor [20], [21] from the perspectives of industrial development, residents' life and ecological protection and promotion, which also provide a basis for protecting ecological security pattern and delineating ecological protection red line [22], [23]. At present, the network analysis method is a more scientific and widely used ecological corridor network construction method [24], which is used to simulate the spatial situation of ecological corridor network and optimize the scheme. As for the technology of corridor construction, the most important thing is the selection of ecological source. Most studies directly select green space, rivers, forest parks or animal and plant nature reserves with good ecological service value as ecological source [25]. Ecological sensitivity analysis is mainly used to guide ecological environment protection and construction [26], scientific land use [27], etc. Ecosystem service value evaluation mainly provides the basis for ecological compensation [28], and guides the optimization of regional land use structure, etc [29]. Many scholars have analyzed and evaluated the ecological space from the aspects of ecological sensitivity and ecosystem services. Research facts have proved that ecological sensitivity analysis and ecosystem service value evaluation are of great significance to improve the carrying capacity of regional ecological environment. Generally speaking, the research on ecological corridor is mainly based on macro-scale and large-scale theoretical analysis, but lacks practical planning and operation research at the small-scale watershed level. At the same time, the most important ecological source in the region is more dependent on the characteristics of the study area, which is relatively direct and weak in quantitative evaluation, and there are few studies on comprehensively judging ecological source by ecological sensitivity and ecosystem service value.

Sanshui River Basin is located in a typical arid area of Loess Plateau, which is an important ecological security barrier and landscape pattern base in Xunyi County, and is a fragile and sensitive area of ecological environment. In this paper, taking Sanshui River Basin in Xunyi as the research object, based on the ecological conditions of Sanshui River Basin, combining ecological sensitivity and ecosystem service value evaluation to identify the source areas, using the minimum path method to simulate the corridor layout scheme, and combining network analysis to optimize the corridor layout, so as to provide scientific guidance for the ecological environment protection of Sanshui River Basin and provide reference for the study of ecological corridor layout in small watershed scale.